[Changes in calcium-dependent potassium channels of isolated smooth muscle cells of the bladder in rats with experimental diabetes].

Activation of large conductance Ca2+-dependent potassium channels (BK channels) influences repolarization of the action potential and the level of the resting potential of detrusor smooth muscle cells (SMC). Overactive bladder syndrome (OBS) is one of the complications of diabetes. Here using whole-cell patch clamp technique we show sizable reduction of depolarization-evoked BK current (lBK) and decrease in the amplitude and frequency of spontaneous transient outward currents (STOCs) in isolated SMC from detrusor of rats with streptozocin-induced diabetes compared to control animals. Under the diabetes IBK density at step depolarization to +50 mV decreased from control value of 15.0+/-0.4 pA/pF to 10.0+/-0.5 pA/pF, whereas the mean values of the STOCs' frequency and amplitude at holding potential -20 mV were reduced from 12.0+/-1.5 Hz to 2.4+/-0.6 Hz and from 0.9+/-0.1 pA/pF to 0.510.1 pA/pF, respectively. Using real time RT-PCR it was found that the expression of mRNA for the BK-channel primary pore-forming KCa1.1-subunit increases under the diabetes, whilst that for the auxiliary BKCabeta1-subunit decreases. It is concluded that the observed changes in the BK-channel currents can enhance excitability of the detrusor SMCs thereby promoting myogenic OBS. However, further studies are needed to determine how the decrease in BKCabeta1 expression under the diabetes impairs functional properties of BK channels and to establish possible changes in calcium signals that modulate channel activation.

[Urothelium-dependent modulation of urinary bladder smooth muscle contractions by menthol].

TRPM8 cold receptor/channel is considered amongst the variety of receptors that support and modulate sensory function of urothelium, although the information regarding this is still quite contradictory. Here we have studied the effects of nonspecific TRPM8 activator menthol on the contractions of the smooth muscle strips of the rat bladder with intact and removed urothelium, and assessed the expression in them of TRPM8 mRNA using semi-quantitative RT-PCR. Menthol (100 microM) decreased the basal tone and the amplitude of spontaneous contractions only in the strips with intact urothelium. Irrespective of the presence of urothelium it similarly inhibited (by approximately 45 %) the contractions evoked by high-potassium depolarization. Contractions induced by muscarinic agonist carbachol (1 microM) were inhibited by menthol much stronger (by approximately 63%) if the urothelium was present than without it (by approximately 12%). Expression of TRPM8 mRNA in urothelium was not detected, whilst in detrusor smooth muscle it was found very low. We conclude that modulation of contractile responses by menthol is most likely explained by its blocking action on voltage-gated calcium channels ofdetrusor smooth muscle cells (SMC) and by menthol-stimulated release from urothelium of some factor(s) with relaxant effects on SMCs. Stimulation of the secretion of these factors from urothelial cells most likely involves menthol-induced, TRPM8-independent mobilization of calcium.

[The laboratory diagnosis of tuberculosis]. / Diagnosticul de laborator al tuberculozei.

The resurgence of tuberculosis and the increasing prevalence of multiple-resistant Mycobacterium tuberculosis strains are the reasons for the need of a rapid diagnosis of this infection. The article provides information about traditional and new methods in the laboratory diagnosis of tuberculosis, comparing their efficacy and rapidity.

[New isatin-derived hydrazones and Mannich bases with possible biological activity]. / Noi hidrazone si baze Mannich derivate de la isatina, cu eventuala activitate biologica.

The paper presents a synthesis of six new Mannich bases, five hydrazones derived from 1-piperidino-methyl-5-R-isatin and three copper complex compounds of 3-(3'-R-phenyl-pyridazinil-hydrazone)-indoline-2-ones (R=H, CH3, OCH3). The structure of the new compounds was confirmed by the results of the elementary and spectral analysis. Pharmacodynamic studies indicated that copper complex compounds present effective biological properties. Thus, it can be seen that the experimental carrageenan-induced inflammatory oedema was 58.3% inhibited by the complex V (R=CH3) after oral administration. Antimicrobial tests revealed that only compound V (R=OCH3) shows a moderate antimicrobial activity against the gram-positive and gram-negative bacteria, used in the test.

[The effect of the combination of vitamin E and C on the oxidative stress parameters in physical exercise]. / Cercetari privind efectul cuplului de vitamine E si C asupra unor parametri de stres oxidativ în exercitiul fizic.

The paper outlines the modification of some antioxidant enzymes and of reduced glutathione studied on physical training induced oxidative stress model. We also assessed vitamin E and C effect. Biochemical determinations were performed on heart homogenate and erythrocytes. Catalase and glutathione peroxidase activity diminished and superoxide dismutase activity increased to a different extent in both tissue samples, while coupled vitamin E and C protection to these tissues equally varied. The glutathione (GSH) pool decreased in erythrocytes and was moderately enhanced in the heart. Either in red blood cells or heart tissue GSH level constancy was maintained by simultaneous administration of vitamins through the experiment (training period). Malondialdehyde concentration revealed a slightly pro-oxidative behaviour of this couple of vitamins that explained the only partial recovery of enzymatic activity to normal values as well as a moderate lipid peroxidation process. Both phenomena were better expressed in erythrocytes.

[The reaction of 3-(R-phenyl)-6-hydrazine pyridazine with 5-methylisatin and 1-morpholinomethyl-5-methylisatin]. / La réaction de la 3-(R-phényle)-6-hydrazino-pyridazine avec la 5-méthyl-isatine et la 1-morpholinométhyl-5-méthyl-isatine.

This paper presents the synthesis of six hydrazones obtained by treating 5-methyl-isatin or 1-morpholino methyl-5-methyl-isatin with 3-(R-phenyl)-6-hydrazino-pyridazine (R = OCH3, Cl, Br) and two complex combination with copper, derived from 3-(p-anisyl-pyridazinyl)-hydrazone-5-methyl-indoline-2- one. The structure of the new compounds was confirmed by the results of the quantitative elementary and IR, UV-VIS spectral analysis. The biological tests point out that product VI, in which a copper atom binds two molecules of 3-(p-anisyl-pyridazinyl)-hydrazono-5-methyl-indoline-2-one, has a considerable antiinflammatory activity, giving a inflammation inhibition of 39, 6%. All the synthetized compounds have a moderate antimicrobial activity against Candida albicans.

Detection of beta-lactamase production and enzyme profiles in Enterobacteriaceae isolated in Moldova.

In our study, out of 449 Enterobacteriaceae strains isolated between 1985 and 1990, 16 strains (3 Proteus, 6 nontyphoidal Salmonella, 7 Escherichia coli) were resistant both to Ampicillin- Sulbactam and Amoxycillin-Clavulanic acid associations. The activity profiles of the beta-lactamases produced by these resistant strains are described. Sarcina lutea ATCC 9341 was used as test strain. The effect of the enzymatic filtrate against beta-lactam antibiotics: Ampicillin, Cloxacillin, Cefadroxil, Cefuroxime, Cefotaxime, Ceftriaxone, was followed up. The enzyme types were established according to the ability of inactivating the tested antibiotics. Penicillins and cephalosporins were inactivated by these enzymes, except for Carbenicillin and Oxacillin. These beta-lactamases were resistant to Sulbactam and Clavulanic acid. In the studied Salmonella strains they are plasmidic codified, demonstrating that they belong to a new beta-lactamase class.